2012/10/18 by D. V. Maheshwar Repaka, Repaka, D. V. Maheshwar, T. S. Tripathi +5
Materials Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1210.5216
20 pages, 11 figures
arxiv created 2012/10/18 · openalex publication_date 2012/10/18 · arxiv updated 2012/10/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have investigated magnetization(M), magnetocaloric effect(MCE) and magnetothermopower(MTEP) in polycrystalline Pr0.6Sr0.4MnO3, which shows a second-order paramagnetic to ferromagnetic transition near room temperature (TC = 305 K). However, field-cooled M(T) within the long range ferromagnetic state shows an abrupt decrease at TS = 86 K for H < 3 T. The low temperature transition is first-order in nature as suggested by the hysteresis in M(T) and exothermic/endothermic peaks in differential thermal analysis for cooling and warming cycles. The anomaly at TS is attributed to a structural transition from orthorhombic to monoclinic phase. The magnetic entropy change is negative at TC but changes to positive at TS. Thermopower (Q) is negative from 350 K to 20 K, shows a rapid decrease at TC and a small cusp around TS in zero field. The MTEP reaches a maximum value of 25% for deltaH = 3 T around TC which is much higher than 15% dc magnetoresistance for the same field change. A linear relation between MTEP and magnetoresistance, and between delta Sm and Delta Q are found near TC. Further, ac magnetotransport in low dc magnetic fields (H less than or equal to 1 kOe), critical analysis of the paramagnetic to ferromagnetic transition and scaling behavior of the magnetic entropy change versus a reduced temperature under different magnetic fields are also reported.